https://github.com/ghetzel/command-deck
A Powerline-inspired PS1 terminal prompt generator.
https://github.com/ghetzel/command-deck
bash i3-wm prompt ps1 terminal
Last synced: 5 months ago
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A Powerline-inspired PS1 terminal prompt generator.
- Host: GitHub
- URL: https://github.com/ghetzel/command-deck
- Owner: ghetzel
- Created: 2019-03-02T20:46:34.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2023-02-18T19:23:16.000Z (over 3 years ago)
- Last Synced: 2024-06-20T11:10:35.548Z (about 2 years ago)
- Topics: bash, i3-wm, prompt, ps1, terminal
- Language: Go
- Homepage:
- Size: 189 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Overview
Command Deck is a simple utility inspired by [Powerline](https://github.com/powerline/powerline) for creating simple, customizable terminal prompts that take advantage of Unicode and high-color terminal environments to create functional, beautiful, and data-rich command prompts.
# Examples
# Installation
Retrieve the program using Golang's `go get` utility:
`go get github.com/ghetzel/command-deck`
And add the following to the end of your `~/.bashrc` file:
```bash
if which cdeck 2>&1 > /dev/null; then
PROMPT_COMMAND='export LASTEXIT=$?; PS1=$(LASTEXIT=$LASTEXIT cdeck)'
fi
```
Note that `$LASTEXIT` is not special in any way. We capture the last exit status via `$?` and store it in this variable, which is explicitly referenced in the configuration file. If you don't need to get the last exit status, you can simply use `PROMPT_COMMAND='PS1=$(cdeck)'` instead.
### "How do I get that cool looking chevron separator?"
The "chevron" is actually a custom full-height character stored in the Private Use Area of pre-modified fonts. You can find the fonts Powerline uses here: https://github.com/powerline/fonts. The examples shown here are using _DejaVu Sans Mono for Powerline (Book)_.
# Usage
CommandDeck is configured in two ways: via positional arguments in _eval_ mode (using the `--eval`/`-e` flag), or via a YAML configuration file located at `~/.config/cdeck.yml`.
## Expressions
Expressions allow for external commands to be evaluated for the purpose of using their output while building prompt segments. Expressions are strings that contain literal text and _command substitutions_, which are surrounded by `{!` and `!}`. When a command substitution is encountered, the command specified will be run and its standard output will be used in place of the substitution. For example, the expression `Hello, {! whoami !}!` would expand to "Hello, ghetzel!".
## Config File
A configuration file is used to specify the individual segments that make up the CommandDeck output. Expressions are accepted in the `fg`, `bg`, `if`, `except`, and `expr` fields. This sample configuration file shows the options that produced the example prompt above:
```yaml
segments:
# Will output the value of the `$LASTEXIT` environment variable with a background color of red and
# a foreground color of *bold* white (ANSI color #15 + "b" for bold), but only if the command `test
# ${LASTEXIT}" -ne 0` exits with status 0.
- name: lastexit
bg: red
fg: '15+b'
if: 'test "${LASTEXIT}" -ne 0'
expr: '{! echo "${LASTEXIT:-?}" !}'
# Output the current HH:MM:SS time by executing `date +%H:%M:%S`. Foreground is grey (ANSI #252,
# "Grey82"), background is darker grey (ANSI #240, "Grey35").
- name: time
fg: 252
bg: 240
expr: "{! date +%H:%M:%S !}"
# Output the current username and hostname as "user@host" by running `whoami` and `hostname -s`
# (respectively). Foreground is white (ANSI #15), background is selected on-the-fly by reading `~/
# .ps1hostcolor`, and falling back to navy blue (ANSI #4).
- name: user
fg: 15
bg: '{! cat ~/.ps1hostcolor || echo 4 !}'
expr: "{! whoami !}@{! hostname -s !}"
# Output the current directory as returned from `pwd`, substiuting the first occurrence of the
# string contained in `${HOME}` with a tilde (~). Foreground is white, background is chartreuse
# (ANSI #64, "Chartreuse4").
- name: path
fg: 15
bg: 64
expr: '{! pwd | sed "s|${HOME}|~|" !}'
# Conditionally output a segment showing the current Git branch. Foreground is white, background
# is determined by the exit status of `test -z "$(git status -s)"`. If it exits successfully,
# there are no modified files in the current repository and the background color will be ANSI #24
# (DeepSkyBlue4). If the command exits non-zero, there _are_ uncommitted changes and the
# background will be ANSI #9 (Red). The commands must exit within 250ms or the segment will not be
# shown. This is a protection measure against terminal slowdown caused by entering large,
# unindexed Git repositories.
- name: git
if: 'git rev-parse --abbrev-ref HEAD'
fg: 15
bg: '{! test -z "$(git status -s)" && echo 24 || echo 9 !}'
expr: "{! git rev-parse --abbrev-ref HEAD !}"
timeout: 250ms
```
## Command Line (Eval Mode)
You can also invoke CommandDeck to print one-off evaluations for various purposes. This approach is useful in a wide variety of circumstances that use text formatted inputs for various purposed (for example, the [i3 window manager's](https://i3wm.org/docs/userguide.html#_configuring_i3bar) `i3-bar` project could be configured this way.)
#### Invocation
```bash
cdeck -e -T ' ' -s '|' \
'::MEM {! free -w -g -h | grep "^Mem" | tr -s " " | cut -d" " -f8 !}' \
"::CPU {! echo $(( $(cat /sys/class/thermal/thermal_zone0/temp) / 1000 )) !}$(printf '\u00B0')C" \
"::LOAD {! cat /proc/loadavg | cut -d' ' -f1-3 !}" \
"::{! date '+%Y-%m-%d %H:%M:%S' !}"
```
#### Output
```
MEM 8.6G | CPU 39°C | LOAD 0.61 0.40 0.32 | 2006-01-02 15:04:05
```
Each positional parameter is specified as a "foreground:background:expression" triple. If either the foreground or background is omitted, the default color for the terminal will be used. The expression is interpreted the same way as expressions in the config file.